<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    /* 相邻选择器会选中紧挨着的下面的那个元素 */
    /* h1+h5 {
      color: aqua;
    } */

    /* 往下找兄弟 */
    h1~h5 {
      color: brown;
    }

    input[value] {
      background: #000;
    }

    #div1 :hover {
      /* color: brown; */
      border: 5px solid red;
    }

    h5.aa {
      background: burlywood;
    }
    input:focus{
      background: red;
    }
  </style>
</head>

<body>

  <div id="div1">
    12345678
    <h5 class="aa">55555</h5>
    <h1>这是个h1</h1>
    <h4>2345678</h4>
    <h5 class="aa">66666</h5>
    <h5>77777</h5>
  </div>



  <input type="text" value="name">
  <input type="text" value="age">
  <input type="text">

  <a href="">跳到首页</a>
  <button>点我</button>



</body>

</html>